1、Designation: D7931 17D7931 18Standard Guide forSpecifying Drainage Geocomposites1This standard is issued under the fixed designation D7931; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pare
2、ntheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide presents a guideline specifying a drainage geocomposite product; it specifically provides recommendations todetermine the allowable flow r
3、ate of a candidate drainage geocomposite. The resulting value is then compared to a required (ordesign) flow rate for a product-specific and site-specific factor of safety.1.2 This guide is intended to aid designers, purchasers, installers, contractors, owners, operators, and agencies in establishin
4、gminimum guidelines for drainage geocomposite materials. This guide is not to be used for manufacturers quality control purposes,nor a construction quality assurance specification.1.3 This guide does not address the required (or design) flow rate value, nor the subsequent factor of safety values, wh
5、ich aretypically design specific.1.4 The procedures recommended in this guide use ASTM test methods.1.5 This guide is applicable to all types of drainage geocomposites regardless of their core configuration or geotextile type. Itcan also be used to evaluate thick, nonwoven geotextiles that provide d
6、rainage.1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in nonconform
7、ance with the standard.1.7 This guide offers an organized collection of information or a series of options and does not recommend a specific courseof action. This guide cannot replace education or experience and should be used in conjunction with professional judgment. Notall aspects of this guide m
8、ay be applicable in all circumstances. This guide is not intended to represent or replace the standard ofcare by which the adequacy of a given professional service must be judged, nor should this guide be applied without considerationof a projects many unique aspects. The word standard in the title
9、of this guide means only that the guide has been approvedthrough the ASTM International consensus process.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, h
10、ealth, and environmental practices and determine the applicability ofregulatory limitations prior to use.1.9 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of Internati
11、onal Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1987 Test Method for Biological Clogging of Geotextile or Soil/Geotextile FiltersD2990 Test Methods for Tensile, Compressive, and F
12、lexural Creep and Creep-Rupture of PlasticsD4354 Practice for Sampling of Geosynthetics and Rolled Erosion Control Products (RECPs) for TestingD4439 Terminology for GeosyntheticsD4716/D4716M Test Method for Determining the (In-plane) Flow Rate per Unit Width and Hydraulic Transmissivity of aGeosynth
13、etic Using a Constant HeadD4873/D4873M Guide for Identification, Storage, and Handling of Geosynthetic Rolls and Samples1 This guide is under the jurisdiction of ASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommittee D35.03 on Permeability and Filtration.Current edition
14、 approved Sept. 1, 2017Feb. 1, 2018. Published September 2017February 2018. Originally approved in 2017. Last previous edition approved in 2017 asD7931 17. DOI: 10.1520/D7931-17.10.1520/D7931-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at s
15、erviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous versio
16、n. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International
17、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D5321/D5321M Test Method for Determining the Shear Strength of Soil-Geosynthetic and Geosynthetic-GeosyntheticInterfaces by Direct ShearD5322 Practice for Laboratory Immersion Procedures for Evaluating the Chemical
18、 Resistance of Geosynthetics to LiquidsD6243/D6243M Test Method for Determining the Internal and Interface Shear Strength of Geosynthetic Clay Liner by the DirectShear MethodD6388 Practice for Tests to Evaluate the Chemical Resistance of Geonets to LiquidsD6389 Practice for Tests to Evaluate the Che
19、mical Resistance of Geotextiles to LiquidsD6747 Guide for Selection of Techniques for Electrical Leak Location of Leaks in GeomembranesD7001 Specification for Geocomposites for Pavement Edge Drains and Other High-Flow ApplicationsD7273/D7273M Guide for Acceptance Testing Requirements for Geonets and
20、 Geonet Drainage GeocompositesD7361 Test Method for Accelerated Compressive Creep of Geosynthetic Materials Based on Time-Temperature SuperpositionUsing the Stepped Isothermal MethodD7406 Test Method for Time-Dependent (Creep) Deformation Under Constant Pressure for Geosynthetic Drainage ProductsD78
21、52 Practice for Use of an Electrically Conductive Geotextile for Leak Location Surveys3. Terminology3.1 Definitions:3.1.1 For definitions of terms related to geosynthetics, refer to Terminology D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 agency, nin geosynthetics, the organization
22、 that reviews the permit application for compliance with the agencysregulation and all quality assurance documentation before and after construction.3.2.2 contractor, nin geosynthetics, the party or organization that has the responsibility for the construction of the man-madeproject, structure, or s
23、ystem.3.2.3 designer, nin geosynthetics, the person or organization that designs a man-made project, structure, or system that fulfillsthe owner/operators requirements and meets or exceeds the minimum requirements of the agency.3.2.4 installer, nin geosynthetics, the party that installs, or facilita
24、tes installation of, any materials purchased frommanufacturers or suppliers.3.2.5 operator, nin geosynthetics, the person or organization that operates the man-made project, structure, or system.3.2.6 owner, nin geosynthetics, the person or organization that owns the man-made project, structure, or
25、system.3.2.7 purchaser, nin geosynthetics, the person, company, or organization that purchases any materials or work to beperformed.3.2.8 q100, ninitial flow rate for a drainage geocomposite as determined under simulated conditions for 100-h duration.3.2.9 qallow, nallowable flow rate for a drainage
26、 geocomposite.4. Significance and Use4.1 This guide is intended to aid designers, purchasers, installers, contractors, owners, operators, and agencies in establishingthe minimum criteria to specify drainage geocomposites. Specifically, this guide presents a methodology for determining theallowable f
27、low rate of a candidate drainage geocomposite. The resulting value is then compared to a required (or design) flow ratefor a product-specific and site-specific factor of safety.4.2 It is recognized that there are other products that may achieve the same performance requirements but are not listed in
28、 thisdocument. Manufacturers of such products are invited to implement this standard guide with the appropriate information.4.3 It should be recognized that parties, organizations, or representatives may perform additional tests other than those requiredin this guide. In this case, the more stringen
29、t project-specific tests will then take precedence.4.4 By simulating site-specific conditions (inclusive of site-specific liquids and temperatures except for load duration beyond100 h, chemical/biological clogging, and geotextile intrusion), additional reduction factors need not be explicitly accoun
30、ted for incertain products.5. Classification5.1 GeneralThis guide covers geocomposite drainage products or structures intended for blanket subsurface drainageapplications. Five distinctly different product designs are included in this guide as geocomposite drainage products:5.2 Biaxial Geonet Geocom
31、positeA geonet consisting of an integrally connected parallel set of ribs overlying a similar set ofribs at typically opposite angles, typically heat laminated with nonwoven geotextiles on the top and bottom to form thegeocomposite. Note that single-sided biaxial geonet geocomposites are available i
32、n the marketplace as well; in that particular case,only one side of the geonet will be heat laminated with a nonwoven geotextile.D7931 1825.3 Triaxial Geonet GeocompositeAgeonet consisting of an integrally connected parallel set of ribs, or forming an integratedweb with a flow direction mainly orien
33、ted in the machine direction, typically heat laminated with nonwoven geotextiles on the topand bottom to form the geonet geocomposite. It should be noted that single-sided triaxial geonet geocomposites are available inthe marketplace as well; in that particular case, only one side of the geonet will
34、 be heat laminated with a nonwoven geotextile.5.4 Multilinear Drainage GeocompositeA manufactured product composed of a series of parallel single drainage conduitsregularly spaced across its width sandwiched between two or more geosynthetics.5.5 Structured Geomembrane SystemAgeomembrane with integra
35、ted drainage nubs, spikes, or both.The drainage nubs, whenoverlain or heat laminated by a filter fabric (heat burnished on one side), will form the structured geomembrane drainagegeocomposite.5.6 Sheet Drain GeocompositeA three-dimensional structured core consisting of integrally connected voids wit
36、h a flowdirection mainly oriented in the machine direction, voids, typically heat laminated with a nonwoven geotextile or monofilamentfilter either on the top or bottom (or both) to form the drainage geocomposite. It should be noted that single-sided sheet draingeocomposites are available in the mar
37、ketplace as well; in that particular case, only one side of the structure will be laminated witha nonwoven geotextile or monofilament filter geotextile.5.7 Geocomposite Edge DrainA geotextile wrapped around a structural polymer drainage core used for subsurface drainageapplications in highway, turf,
38、 and environmental applications. The product is typically 1 in. (25 mm) thick and available in 6 in.(150 mm), 12 in. (300 mm), 18 in. (450 mm), 24 in. (600 mm), 30 in. (750 mm), and 36 in. (900 mm) widths.6. Determination of the qallow of a Candidate Drainage Geocomposite6.1 Basic Formulation3This g
39、uide is focused on determination of a qallow value using the following formula:qallow 5q100F 1RFCR1RFCC1RFBC1RFGIG (1)qallow 5q100F 1RFCR 3RFCC 3RFBC 3RFGIG (1)where:qallow = allowable flow rate for a drainage geocomposite,q100 = initial flow rate determined under simulated conditions for 100-h dura
40、tion,RFCR = reduction factor for creep to account for long-term behavior,RFCC = reduction factor for chemical clogging,RFBC = reduction factor for biological clogging, andRFGI = reduction factor for geotextile intrusion past the initial 100-h seating time.NOTE 1The value of qallow is typically used
41、to determine the product-specific and site-specific flow rate factor of safety as follows:FS5qallowqreqd(2)The value of qreqd is a design issue and is not addressed in this guide. Likewise, the numeric value of the factor of safety is not addressed in thisguide. Suffice it to say that, depending on
42、the duration and criticality of the situation, FS values should be conservative unless experience allowsotherwise.6.2 Upon selecting the candidate drainage geocomposite product, one must obtain the 100-h duration flow rate according to theTest Method D4716/D4716M transmissivity test or other appropr
43、iate transmissivity test method such as Specification D7001,which is more appropriate for high-flow applications (seeapplications. (See 6.2.2 for more background on which transmissivity testmethod to select).select.) This establishes the base value to which drainage core creep beyond 100 h, clogging
44、 from chemicals andbiological matter, and geotextile intrusion must be accounted for.6.2.1 It is recognized that the default duration listed in Test Method D4716/D4716M is 15 min. This guide purposely requiresthat the test conditions be maintained for 100 h, and simulating site-specific loading and
45、boundary conditions.6.2.2 While Test Method D4716/D4716M has historically been the “default” transmissivity test for geosynthetic drainagegeocomposites, this transmissivity test method is limited to the size of the specimen being tested. Zimmel et al. (2011) identifiedthat specimen size can signific
46、antly affect transmissivity tests performed in accordance with Test Method D4716/D4716M;however, recent research has shown that Test Method D4716/D4716M typically underestimates the actual flow rates at a certain3 This guide is updated and modified from GRI-GC 8 “Determination of the Allowable Flow
47、Rate of a Drainage Geocomposite” to reflect different products in themarketplace today. For referenced GRI standards, visit the GSI website, http:/www.geosyntheticinstitute.org/, or contact GSI Customer Service at (610) 522-8440. GRIstandards are developed by the Geosynthetics Research Institute thr
48、ough consultation and review by the member organizations.D7931 183hydraulic gradient (tested with a large-scale transmissivimeter), at least for unidirectional drainage geocomposites, and as a resultTest Method D4716/D4716M transmissivity results are typically conservative.6.2.3 Furthermore, standar
49、d engineering practice identifies that the transmissivity is only valid for laminar flow conditions,specifically when Darcys law is valid, and then the transmissivity is an intrinsic property of the product and not dependent onexternal conditions such as the hydraulic gradient. According to Darcys law, transmissivity should be a constant. However,transmissivity testing of drainage geocomposites has shown that transmissivity is not a constant, but is associated not only withthe normal load but also with the hydraulic gradient and selected boundary condi
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